One of the final steps in the refining of copper is an electroplating step, where the copper is electroplated onto metallic plates. In particular, copper anodes (of about 99% pure copper) are placed within a sulfuric acid solution, and an electrical charge is induced between the anodes and a plurality of metallic plates acting as cathodes. The copper from the anodes electroplates onto exposed metallic surface of the cathodes, with the electroplated copper being about 99.9% pure.
If no portion of the cathode suspended within the sulfuric acid solution is protected from the sulfuric acid solution, then the copper electroplated completely encases the portion of the cathode suspended within the sulfuric acid solution. However, having the copper completely encase the cathode makes removal of the copper difficult. In order to ease removing the electroplated copper from the cathode, the edge of the cathode is protected from contact with sulfuric acid solution, and thus the copper does not electroplate onto the protected edge.
In the related art, the edge of the cathode is protected by tape adhered to the edge of the cathode, along with a plastic clip with a “C” shape cross-section placed over the tape. Coupling of the plastic clip is merely by clamping force exerted by outward displacement of the “C” shape structure. The thickness of the cathodes may vary with age of the cathode, and thus the clamping force exerted by the “C” shape is inconsistent. In other cases, non-metallic fasteners may couple to the “C” shaped plastic clip through the underlying cathode to assist in keeping the plastic clip attached. Thus, regardless of the precise mechanism utilized to attach the plastic clip, the plastic clip does not adhere to the underlying cathode.
However, the cathodes are subject to bending and flexing during handling. Further, the cathodes are also subject to being struck by, and striking, other cathodes and anodes during placement into and removal from the sulfuric acid solution tanks. The flexing and striking tends to damage the “C” shaped plastic clips and/or the tape. In some cases, the tape and “C” shaped plastic clips may last as few as three days before needing replacement, and rarely will the “C” shaped plastic clips and tape last more than three months. Damaged cathodes may produce irregularly shaped copper pieces, or copper pieces that are difficult to remove from the cathodes.
Thus, any advance in protecting the edges of the metallic cathodes would reduce cost of the electroplating process, and provide a competitive advantage.